How to retreive the hotkey of a function/tool?
You need to have some clue about how each command is executed (i.e. the operator) in order to find its hotkeys, but if you do, it's not too difficult:

wm            = bpy.context.window_manager                       # Blender window manager
keymaps_3DV   = wm.keyconfigs['Blender'].keymaps['3D View']      # 3D View hotkeys
circle_keymap = keymaps_3DV.keymap_items['view3d.select_circle'] # Circle select keymap object
main_key      = circle_keymap.type                               # "C" in this case


If you want to see if any modifier key is used, or if the ALT / SHIFT / CTRL keys are used, you can access this info this way:

modifier_key = circle_keymap.key_modifier   # Is 'NONE' in this case
shift        = circle_keymap.shift          # Is False in this case
ctrl         = circle_keymap.ctrl           # Is False in this case
alt          = circle_keymap.alt            # You've guessed it


There's lots of other interesting properties of hotkeys to investigate, but I'll leave it to you.

To see the rotate operator's hotkey, access it thus:

circle_keymap = keymaps_3DV.keymap_items['transform.rotate']